package com.chenhao.springcloud.chenhaodatastructureservice.stack;

import java.util.Stack;

/**
 * Description:20有效的括号
 *
 * @author chenhao
 * @date 2020/12/8 11:02
 */
public class Solution {
    public boolean isValid(String s){
        Stack<Character> stack = new Stack <>();
        for (int i = 0;i<s.length();i++){
            char c = s.charAt(i);
            if (c=='(' ||c=='['||c=='{'){
                stack.push(c);
            }else {
                if (stack.isEmpty()){
                    return false;
                }
                char topChar = stack.pop();
                if ((c==')') && topChar!='('){
                    return false;
                }
                if ((c=='}') && topChar!='{'){
                    return false;
                }
                if ((c==']') && topChar!='['){
                    return false;
                }
            }
        }
        return stack.isEmpty();
    }
}
